Products derived from isoindole of general formula: ##STR3## which exhibit opium activity, have been described in U.S. Pat. No. 4,042,707.
These products exhibit no activity towards substance P and neither can they be used as intermediates leading to such products.
In spite of the research carried out and in spite of the interest created [M. R. Hanley, TINS, (5) 139 (1982)], practically no product had been discovered so far which acts specifically on substance P and which has a nonpeptide structure; accordingly, the isoindole derivatives of general formula (I) are of great interest.